Maybe I'll get lucky and the Devs will see this (Or one that remebers at least). About 3 - 4, maybe 5 years ago, the Devs went to the/a Heartland Game Convention and they let me put a dev demo of the game on my little Blue 1GB USB Drive I had (I was 12, 13 or 14 at the time) and I still have it to this day, I boot it up once and a while to remeber, I might even buy the full game once I have enough money. Anyway Just a little story that I hope the devs will see.

On level 4, towards the bottom of the level, you will see an orbit line. Occasionally, one of those spheres will come along, and from exiting the system with the giant hot object, you will be able to orbit around this rogue sphere. You can't capture this sphere. Instead, a shield forms around the sphere, and takes you to a hidden part of the level, where there are 3 systems and a total of 5 of the bright white flying sprites, of which one can be found earlier in the level. Was this one of the secrets you were talking about Evil Aliens?